There isn’t much of a chance to cheat this particular test. The subject is almost completely limited to attempting to make the collection of the sample impossible. The subject may become extremely agitated or even fake a medical panic at the thought of the blood draw. Another common strategy would be to claim some religious objection to the process. If all else fails, the subject may resort to simply jerking their body in pseudo fear to make successful venous access near impossible.
There are extremely rare circumstances where this sample type is used. The test itself can sometimes last up to 14 days. A patch is placed on the test subject that will continuously collect perspiration for later testing. Government institutions make up for almost all of this type of testing. The subjects are suspected of long-term drug use. They include people on parole or involved in a case with child welfare services. The other biggest employer of this test is the official entities that exist to test professional athletes for performance-enhancing drugs. These agencies have very complex and heavily tested systems in place to prevent cheating. If drug tests are cheated at this level, it will often be on the evening news.
The most common method to cheat these tests involves damaging or altering the patch used to collect the sample in some way. Another version of this strategy is to somehow misplace the patch through a perceived accident. The subject will usually attempt to poke holes in the patch and drain their perspiration from within. They will then re-saturate the pad with the perspiration of a person who does not have any prohibited substances in their system. Most subjects will feel safe assuming their drug test will not be the sweat sample type.